Two identical ball bearings in contact with each other and resting on a frictionless table are hit head on by another ball bearing of the same mass moving initially with a speed v, figure,. If the collision is elastic, which of the following is a possible result after collisioin?

Explanation

(ii) is a possible collision .
Let m be the mass of each collision ` = 1/2 mv^(2)`
Final kinetic energy for the given case :
Case I `E_(1) = 1/2 (2m) (v/s)^(2) = 1/4 mv^(2)`
Case II `E_(2) = 1/2 mv^(2)`
Case III `E_(3) = 1/2 (3m) (v/3)^(2) = 1/6 mv^(2)`
As kinetic energy is conserved only in Case II . Therefore , case II is the only possibility .